Optical waveguides are key components in modern telecommunications systems. Optical waveguides are typically in the form of optical fibers or "planar" waveguides. In essence, an optical fiber is a small diameter circular waveguide characterized by a core with a first index of refraction surrounded by a cladding having a second (lower) index of refraction. It is capable of transmitting an optical signal containing a large amount of information over long distances. A planar waveguide is usually a substrate-supported waveguide of rectangular cross section. It also has a core and a cladding. Planar waveguides are typically much shorter than fibers, but can be formed in complex configurations. Typical optical waveguides are made of high purity silica with minor concentrations of dopants to control the index of refraction.
A typical optical system comprises a source of optical input signals, a network of optical waveguides coupled to the source, and one or more receivers coupled to the waveguide for receiving the optical signal. Amplifying devices such as rare-earth doped amplifiers can be disposed at various points in the network. Contemplated WDM telecommunications systems would employ wavelength division multiplexing using many different wavelength channels to convey information between points in the network. Contemplated optical data processing applications would employ similar networks on a much smaller distance scale.
Optical switching devices are key components in optical communications and processing networks. Switches are essential for routing communications or data channels from one point in the network to another.
Conventional optical switching devices are mainly hybrid devices using electro-optical or electromechanical effects. They are typically slow, expensive and lossy. They must be inserted into the system by cutting and splicing with high precision alignment. Accordingly there is a need for a simple, fast, efficient optical switching device.